chore: upgrade supported language versions (#129)

Author: childish-sambino

.github/workflows/test-and-deploy.yml

@@ -17,7 +17,7 @@ jobs:
     timeout-minutes: 20
     strategy:
       matrix:
-        ruby: [ 2.4, 2.5, 2.6, 2.7, jruby-9.2 ]
+        ruby: [ '2.4', '2.5', '2.6', '2.7', '3.0', '3.1', 'jruby-9.2' ]
     steps:
       - name: Checkout ruby-http-client
         uses: actions/checkout@v2
@@ -59,7 +59,7 @@ jobs:
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
-          ruby-version: 2.4
+          ruby-version: 3.1
           bundler-cache: true
 
       - run: make install